FR2776285A1 - A water soluble or water dispersible dispersing agent - Google Patents

Abstract

A water soluble or water dispersible dispersing agent is obtained by the partial esterification of at least one polyacid and at least one polyether. A water soluble or water dispersible dispersing agent for cement compositions and aqueous mineral particle suspensions, containing polyether chains and optionally partly or totally salified carboxylic functions is obtained by base catalyzed partial esterification involving the reaction of: (a) at least one polycarboxylic acid containing at least 6 carboxylic functions per molecule obtained by the polymerization of at least one unsaturated carboxylic acid; and (b) at least one polyether containing a free hydroxyl group which can react with a carboxylic function. Independent claims are also included for: (1) a method of preparing said agent; (2) a combination of dispersing agents containing said agent; (3) an additive containing said agent; and (4) the use of said agent in cement and mineral particle suspensions as, e.g. a fluidizer.

Description

The subject of the invention is a water-soluble or water-dispersible dispersant for cement compositions and aqueous suspensions of mineral particles. The invention also relates to adjuvants containing such a dispersant.

Dispersants, water-soluble or water-dispersible, for cement compositions, such as grouts, mortars and concretes, for reducing the water content with a high retention of workability (ie maintenance of fluidity or low sagging loss), are well known and used for many years. These water-soluble dispersants are sometimes referred to as water reducers or fluidifiers, or plasticizers, or superplasticizers. These water-soluble dispersants make it possible to obtain cement compositions with the desired consistency with reduced water contents and, consequently, an improvement in the mechanical strengths of the hardened cement compositions. In recent years, water-soluble dispersants based on polycarboxylate, having the above characteristics, have been developed.

A water-soluble or water-dispersible dispersant has now been found which, for reduced water-content cement compositions, allows a prolonged maintenance of the fluidity, associated with high values of strengths, in particular high values of compressive strengths at young ages. (That is, 24 hours after the preparation of the cement compositions containing this dispersant).

More specifically, the water-soluble or water-dispersible dispersant according to the invention is suitable for cement compositions and aqueous suspensions of mineral particles, contains acidic carboxylic functions, optionally partially or totally salified, and polyether chains. This dispersant is characterized in that it is obtained by partial esterification catalyzed by the introduction of a base, by reacting
at least one polycarboxylic acid obtained in
polymerizing at least one non-carboxylic acid
saturated, containing on average at least six functions
carboxylic acids per molecule;
and at least one polyether containing a hydroxyl group
free to react with a carboxylic function
of said polycarboxylic acid, preferably a group
terminal hydroxyl.

A difference between the dispersant of the present invention and the known polycarboxylate dispersants is that it is obtained by partial esterification catalyzed by the addition of a base.

However, such an esterification does not lead to the rupture of the polyether molecules, so that the weight average molecular weight of the polyether before esterification is equal to that of the polyether chains of the dispersant according to the invention. In addition, it has been found that the dispersants according to the invention have the aforementioned properties, in particular make it possible to prepare particularly homogeneous cement compositions (little or no segregation and little or no bleeding) but sufficiently flowable to be easy to remove. put in place and that lead to compressive strengths at young high ages.

Preferably, the base used for the partial esterification is an alkali metal hydroxide, preferably sodium hydroxide or lithium hydroxide. As a base, it is also possible to use a tertiary amine.

Advantageously, the partial esterification reaction is conducted in order to esterify 10 to 90% of the available carboxylic functions of the polycarboxylic acid. Very satisfactory performance (in terms of reduction of the water content, maintenance over time of the fluidity and mechanical strength at young ages) were obtained with a dispersant according to the invention, 30 to 70% of the carboxylic functions were esterified with a polyether or a mixture of polyethers. The best maintenance of fluidity over time has been obtained when at least 50% of the carboxylic functions are esterified with a polyether or a mixture of polyethers.

The weight average molecular weight, "Mw", of the dispersant according to the invention, measured by gel permeation liquid chromatography, with a polyethylene glycol calibration, generally varies between about 1000 and about 1,000,000, preferably between about 10,000 and 10,000. about 80,000.

Preferably, the polycarboxylic acid used to prepare the water-soluble dispersant according to the invention is obtained by polymerization of a monomer mixture containing, as essential component, acrylic acid and / or methacrylic acid (hereinafter referred to as acid (meth) )acrylic).

Optionally, the polycarboxylic acid is also based on at least one comonomer with one or more ethylenic unsaturations which can be copolymerized with (meth) acrylic acid, such as a (meth) acrylic acid ester, for example methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, an alkylene glycol (meth) acrylate, a polyethylene glycol (meth) acrylate, and the like. ; an unsaturated dicarboxylic acid, for example maleic acid, fumaric acid, itaconic acid, citraconic acid, etc., or a corresponding anhydride, or an ester of these unsaturated dicarboxylic acids; unsaturated amides, for example methacrylamide, etc. aromatic vinyls, for example styrene, etc. ; unsaturated sulfonates eg vinyl sulfonates and their salts, etc. ; monomers with a double ethylenic double unsaturation, preferably at most 5% by weight, for example divinylbenzene, or a mixture of the abovementioned comonomers.

This polycarboxylic acid is, more preferably, a homopolymer of acrylic acid or a copolymer of acrylic acid and methacrylic acid.

The weight average molecular weight of the polycarboxylic acid is preferably between 500 and 60,000.

The polycarboxylic acid to be esterified is preferably an aqueous solution miscible with the polyether (s) or a solid soluble in the polyether (s).

The polyether containing a free hydroxyl group, used to prepare the dispersant according to the invention, is advantageously a polyalkylene glycol alkyl ether, preferably a polyalkylene glycol alkyl ether mixture of formula XO- (YO) nH in which
X represents an alkyl group of 1 to 8 atoms of
carbon, preferably from 1 to 4 carbon atoms,
even better, X is a methyl radical;
Y represents an alkylene group of 2 to 4 carbon atoms
carbon or a mixture of these alkylene groups
n is an integer ranging from 3 to 500
the polyalkylene glycol alkyl ether or the mixture
polyalkylene glycol alkyl ethers is such that the
average molar ratio of oxyethylene units on
oxyalkylene units (YO) range from about 0.5 to 1,
even better from 0.7 to 1.

Thus, subject to meeting the above conditions, a polyalkylene glycol alkyl ether mixture may contain one or more polyalkylene glycol alkyl ethers of the formula XO- (YO) n-H wherein Y is not ethylene.

Preferably, the polyether is constituted
one or more polyethylene alkyl ethers
glycol, possibly containing units
oxypropylenes, distinguished by their weight
average molecular weight, or
one or more polypropylene alkylethers
glycol, containing oxyethylene units, is
distinguishing by their average molecular weight by weight,
or
a mixture of these alkyl ethers.

Particularly satisfactory results have been achieved with the dispersants according to the invention obtained from at least one polycarboxylic acid containing on average at least 6 carboxylic functions per molecule and at least one polyether containing a free hydroxyl group chosen from
a polyethylene glycol methyl ether (in the formula
above, X is a methyl radical, Y is a group
ethylene) containing from 10 to 150 units
oxyethylenes (n is from about 10 to 150);
- or a mixture of polyethylene glycol methyl ethers
which differ essentially in length
of their chain of oxyethylene units, this mixture
containing, on average per molecule, of the order of 5 to
50 oxyethylene units.

In addition to the polyalkylene glycol (or) alkyl ether (s), one or more polyethers carrying at least two free hydroxyl groups may be provided in the reaction medium, in a limited amount.

Also, it is possible, in limited quantity, to provide a polyalkylene glycol or a mixture of polyalkylene glycols comprising an alkyl, aryl or alkyl aryl chain, branched or unbranched, of 8 to 22 carbon atoms. The amount of these polyalkylene glycols is preferably less than 2 mol%, based on the number of carboxylic functions of the polycarboxylic acid.

The dispersant according to the invention can be used with compositions based on hydraulic cement such as Portland cements; aluminous cements; various composite cements (CM2 or CM3) constituted by mixing, before or after grinding, Portland clinker and slag, natural pozzolans and / or fly ash; or hydraulic materials other than cement, such as hydraulic calcium sulphates, binders containing
CSA (calcium sulfoaluminate), hydraulic glasses, magnesium and phosphatic binders.

The dispersant according to the invention gives excellent performance even when i. is used in a small amount, generally from 0.05% to 1.5%, preferably from 0.08% to 1% by weight, based on the weight of cement.

The dispersant according to the invention can be added to aqueous suspensions of mineral fillers without hydraulic setting, as a plasticizer. Thus, the dispersant according to the invention is suitable for aqueous suspensions of mineral fillers such as calcium such as calcium carbonate, lime or calcium fluoride; inorganic oxides such as titanium dioxide; ferric oxide, chromium oxide, silica or aluminas; or other fillers such as silicates such as mica, etc.

The dispersant according to the invention is advantageously obtained by adding a base in an aqueous reaction medium and reacting at a temperature between 160 and 2000 ° C.
at least one polycarboxylic acid obtained by
polymerization of at least one non-carboxylic acid
saturated, containing on average at least 6 functions
carboxylic acids per molecule
and at least one polyether containing a hydroxyl group
free to react with a carboxylic function
of said polycarboxylic acid.

When the base is lithium hydroxide, it is preferable to add at least 0.04 mol% of LioH, H 2 O to the reaction medium, this percentage being related to the number of carboxylic functions of the polycarboxylic acid. More preferably, the amount of lithium hydroxide will be at most 10 mol% relative to the number of carboxylic functions of the polycarboxylic acid.

In addition, the partial esterification reaction is preferably conducted under reduced pressure to gradually remove the water formed during the esterification reaction. The reduced pressure is generally between about 133 Pa and about 13340 Pa (1100 mmHg).

The esterification reaction is stopped as soon as the target percentage of esterified carboxylic functions of the polycarboxylic acid is reached.

For the sake of clarity, in the following description, the dispersant according to the invention, which has just been described in detail, will be called "dispersant (Dl)".

The dispersant (D1) may be used in combination with other known additives such as, for example, another dispersant, thickener, antifoaming agent, mass water repellent, retarder or curing accelerator.

The present invention also relates to adjuvants containing the dispersant (D1).

dans laquelle R R est un atome d'hydrogène ou un groupe hydrocarboné
monovalent saturé ou non comportant de 1 à 18 atomes
de carbone et éventuellement un ou plusieurs
hétéroatomes,
les Ri sont semblables ou différents entre eux et
représentent un alkylène comme l'éthylène, le
propylène, le butylène, l'amylène, l'octylène ou le
cyclohexène, ou un arylène comme le styrène ou le
méthylstyrène ; les Ri renferment éventuellement un ou
plusieurs hétéroatomes,
Q est un groupe hydrocarboné comportant de 2 à 18
atomes de carbone et éventuellement un ou plusieurs
hétéroatomes,
A A est un groupe alkylidène comportant de 1 à 5 atomes
de carbone.
les Rj sont semblables ou différents entre eux et
peuvent être choisis parmi:
* le groupe A-P03H2, A ayant la signification
précitée,
* le groupe alkyle comportant de 1 à 18 inclus
atomes de carbone et pouvant porter des
groupements [R-O(Ri-O)n], R et Ri ayant les
significations précitées,
* et le groupe

A first adjuvant (Al) consists of a combination of dispersing agents, characterized in that it consists of at least one dispersant (D1) and at least one dispersant (D2), water-soluble or water-dispersible, comprising at least one amino-alkylene phosphonic group, optionally salified, and at least one polyoxyalkylated chain, and corresponding to the formula

wherein RR is a hydrogen atom or a hydrocarbon group
monovalent saturated or unsaturated having from 1 to 18 atoms
of carbon and possibly one or more
heteroatoms,
the Ri's are similar or different to each other and
represent an alkylene such as ethylene,
propylene, butylene, amylene, octylene or
cyclohexene, or an arylene such as styrene or
methylstyrene; the Ri may contain one or
several heteroatoms,
Q is a hydrocarbon group having from 2 to 18
carbon atoms and possibly one or more
heteroatoms,
AA is an alkylidene group having 1 to 5 atoms
of carbon.
the Rj are similar or different from each other and
can be chosen from:
* the group A-P03H2, A having the meaning
supra,
the alkyl group having from 1 to 18 inclusive
carbon atoms and can carry
groups [RO (Ri-O) n], R and Ri having the
aforementioned meanings,
* and the group

- Rk designating a group such as Rj,
B denotes an alkylene group containing
2 to 18 carbon atoms,
"n" is a number greater than 0,
. "r" is the number of groups [RO (Ri-O) n] carried by
the set of Rj,
"q" is the number of groups [RO (Ri0) n] carried by
Q,
the sum "r + q" is between 1 and 10,
"y" is an integer from 1 to 3,
. Q, N and Rj may together form one or more
cycles, this or these cycles may furthermore
contain one or more other heteroatoms.

dans laquelle . R est un atome d'hydrogène ou un groupe hydrocarboné monovalent, saturé ou non, comportant de 1 à 8 atomes de carbone et, éventuellement, un ou plusieurs hétéroatomes ; les Ri représentent l'éthylène ou le propylène ou un mélange d'éthylène et de propylène. De préférence, 60 à 100 % des Ri sont des groupes éthylène . Q est un groupe hydrocarboné comportant de 2 à 8 atomes de carbone et, éventuellement, un ou plusieurs hétéroatomes ; . A est le groupe méthylène les Rj sont semblables ou différents entre eux et peuvent être choisis parmi * le groupe CH2-P03H2, * et le groupe

Preferably, the dispersant (D2), combined with the dispersant (D1) in the first adjuvant (Al) mentioned above, corresponds to the formula

in which . R is a hydrogen atom or a monovalent hydrocarbon group, saturated or unsaturated, having from 1 to 8 carbon atoms and, optionally, one or more heteroatoms; R 1 represents ethylene or propylene or a mixture of ethylene and propylene. Preferably, 60 to 100% of the R1 are ethylene groups. Q is a hydrocarbon group having 2 to 8 carbon atoms and optionally one or more heteroatoms; . A is the methylene group R 1 is the same or different from each other and may be selected from the group CH 2 -PO 3 H 2, and the group

- Rk denoting a phosphonic group such as Rj,
B denotes an alkylene group containing
2 to 4 carbon atoms,
"n" is an integer between lo and 250,
"q" is an integer equal to 1 or 2,
"y" is an integer equal to 1 or 2.

The ratio by weight of the dispersant (D1) to the dispersant (D2) can vary within wide limits: from 1/99 to 99/1.

The combination of dispersants (D1) and (D2) makes it possible to prepare cement compositions and aqueous suspensions of mineral particles with the desired fluidity with reduced water contents. In addition, by varying the proportion of the dispersant (D1) on the dispersant (D2), it is possible to modulate the maintenance of the fluidity over time of the cement compositions, in particular cementitious compound cement compositions (CM2 or CM3).

A second adjuvant (A2) containing the dispersant (D1) is characterized in that it is in the form of a uniform mixture comprising
- some water
at least one water-insoluble anti-foam agent or
weakly water soluble
at least one water-soluble dispersant (D1) or
water-dispersible, possibly in combination with
at least one dispersant (D2) mentioned above
at least one organic compound (C) containing
at least one primary, secondary or secondary amine function
tertiary, possibly partially or totally
neutralized with a Brönsted acid, organic or
mineral
and at least one alkyl or alkyl-aryl chain,
linear or branched, saturated or unsaturated, comprising
at least 8 carbon atoms, and possibly
heteroatoms, selected from oxygen, sulfur or
nitrogen;
at least one mineral stabilizer when the pH of said
mixture is greater than 7
- optionally, an acid or a base to adjust the
pH of said mixture.

In the adjuvant (A2), the term "antifoam agent which is not water-soluble or slightly water-soluble" means an antifoaming agent that is poorly or not soluble in aqueous media at room temperature (around 20 ° C.) and at atmospheric pressure. "uniform" means a mixture which, when allowed to stand, may range from a clear mixture (such as a microemulsion) to a cloudy mixture (such as an oil-in-water emulsion), sometimes a thin film, usually foam, may be present on the surface of the uniform mixture.

Thanks to the adjuvant (A2), the following results were achieved - the adjuvant (A2) has, for a large variety of antifoam agents with little or no water-soluble and a wide variety of water-soluble or water-dispersible additives, better stability storage relative to a control free of the organic compound (C) described above. Indeed, the adjuvant (A2) remains a uniform mixture for at least 24 hours; the adjuvant (A2) may be marketed in the form of a ready-to-use packaging, more or less concentrated, to be diluted optionally before use.

Advantageously, the dry extract of the adjuvant (A2) varies between about 5% by weight and about 80% by weight, preferably between about 10% by weight and about 70% by weight, more preferably between about 20% by weight. and about 60% by weight.

the adjuvant (A2) is dispersible in the aqueous suspensions of mineral particles and the mixtures based on hydraulic binder, and the defoaming agent that it contains can then act effectively to reduce the volume of entrained air.

The pH of the adjuvant (A2) can be acidic (less than 7) or basic (greater than 7).

When its pH is basic, the adjuvant (A2) necessarily comprises at least one mineral stabilizer which contributes to maintain the uniform mixture. On the other hand, when the pH of the adjuvant (A2) is acidic, the addition of a mineral stabilizer is not essential.

The particle size of the inorganic stabilizer, which consists of finely divided grains, is preferably such that at least 90% of the grains pass through a sieve with square mesh of 50 m side, more preferably 10 m side.

Preferably, the mineral stabilizer has the ability to develop an additional viscosity under the effect of a shear rate and in the presence of water, for example when using ball mills or high speed mixers equipped with water. pale deflocculous. As an example of mineral stabilizer, there may be mentioned clays, such as sepiolites, bentonites or a mixture of these types of clays. The best results were obtained with sepiolites.

Advantageously, the sepiolites are used in a proportion of 0.5% to 2.5% by weight relative to the total wet weight of the adjuvant (A2).

When the adjuvant (A2) is free of mineral stabilizer, the pH of the adjuvant (A2) must be acidic (less than 7), preferably less than or equal to 6, and more preferably between 2 and 6 (inclusive). Indeed, at a pH greater than or equal to 7, in the absence of mineral stabilizer, the stability and, consequently, the homogeneity of the adjuvant (A2) disappear: the uniform mixture usually becomes unstable, c that is, a separation of the organic and aqueous phases is observed.

One of the essential constituents of the adjuvant (A2) according to the invention is an organic compound (C) containing at least one primary, secondary or tertiary amine function, optionally partially or completely neutralized with a Brönsted acid, and at least one an alkyl or alkyl-aryl chain, linear or branched, saturated or unsaturated, this chain comprising at least 8 carbon atoms, preferably at least 12 carbon atoms, and optionally heteroatoms chosen from oxygen, sulfur or nitrogen: in the following description, it will be referred to simply as the "organic compound (C)".

 It has been found that the organic compound (C) maintains the uniformity of the adjuvant (A2) for 24 hours or more. The organic compound (C) thus constitutes the organic stabilizer of the adjuvant (A2).

The adjuvant (A2) can contain, as organic stabilizer, several organic compounds (C) of different chemical nature.

dans laquelle - R4 est une chaîne alkyle ou alkyle-aryle, linéaire ou ramifiée, saturée ou insaturée, contenant au moins 8 atomes de carbone, de préférence au moins 12 atomes de carbone, encore mieux au plus 22 atomes de carbone.According to a preferred variant of the invention, the formula of the organic compound (C) is

in which - R4 is a linear or branched, saturated or unsaturated alkyl or alkyl-aryl chain containing at least 8 carbon atoms, preferably at least 12 carbon atoms, more preferably at most 22 carbon atoms.

Optionally, R4 may comprise one or more heteroatoms selected from oxygen, nitrogen or sulfur to form functional groups such as ether or thioether groups or alcohol or thioalcohol groups; R 5 is a hydrogen atom, or a chain of R 7 -O oxyalkylene units or the R 7 are the same or different from each other and represent an alkylene such as ethylene, propylene or butylene, this chain of R 7 -O oxyalkylene units; having in the terminal position a hydrogen atom or an alkyl or alkyl-aryl group; R 6 is a hydrogen atom or a radical independently selected from the abovementioned definitions for R 4 and R 5; the total number of units (R7 -O) that may be present in R5 and R6, when R7 is ethylene, is preferably at most equal to 12, more preferably at most equal to 8.

The total number of units (R7-0) when R7 is propylene or butylene is not critical. However, the total number of such patterns will preferably be at most 5.

Preferably, the number of nitrogen functional groups in the organic compound (C) is at most equal to 2
The preferred organic compounds (C), with which very satisfactory results have been obtained, are oleic amine and oleic amine derivatives, optionally containing (R7-O) units according to the definitions and conditions mentioned hereinabove. description. This oleic amine is optionally mixed with other organic compounds (C) of different chemical nature. The best results were obtained with the following amines, protonated or not: oleic amine, coconut amine and tallow amine, each of these amines having one mole of ethylene oxide; oleic amine with five moles of ethylene oxide; N, N-bis (2-hydroxyethyl) oleylamine (or oleic amine with two moles of ethylene oxide). Satisfactory results have also been obtained with the amines which follow, protonated or not: the tallow amine with five moles of ethylene oxide, the amine of tallow with seven moles of ethylene oxide, the amine copra to two moles of ethylene oxide.

As indicated above, the organic compound (A) may comprise two nitrogen functional groups and thus belong to the family of diamines. By way of example, mention may be made of N, N ', N'-tri (2-hydroxyethyl) N-tallowpropylene diamine.

In the adjuvant (A2), in combination with the dispersant (D1), one or more water-soluble or water-dispersible additives may be provided, chosen from dispersants (D2), agents which make it possible to reduce the amount of mixing water, and dispersants. , plasticizers, plasticizers, water-repellent agents, retarders or setting or hardening accelerators or a mixture of the abovementioned additives.

Among the water-insoluble or poorly water-soluble antifoam agents suitable for the adjuvant (A2), mention may be made of mineral oils, phosphoric esters, ethylene oxide / propylene oxide copolymers and alkyl polyalkoxy esters. Preferably, the antifoam agents retained are those which are miscible with the organic compounds (C) described above, that is to say those which can lead to a homogeneous mixture with one of these organic compounds (C). More preferably, they are selected from the family of phosphoric esters.

The quantity of organic compound (C) to be expected depends on the composition of the adjuvant (A2). A weight ratio of organic compound (C) / antifoam agent of between approximately 0.01 and approximately 5 is preferably used.

Generally, an excess of organic compound (C) relative to the amount necessary for the stability of the adjuvant (A2) is not desirable first of all for short reasons of the formulation, and also because of the volume in air which can be entrained in the case where this organic compound (C) has an emulsifying power even in neutral pH (equal to 7) or basic pH environment.

The weight ratio of antifoam / dispersant (D1) optionally combined with another water-soluble or water-dispersible additive) is generally from about 0.002 to about 0.5, preferably from about 0.005 to about 0.1.

The adjuvant (A2) may optionally contain other compounds, provided that they do not appreciably affect the stability of the emulsion. These optional compounds are preferably water-soluble and are, for example, air entrainers.

Preferably, the adjuvant (A2) is prepared in concentrated form, in the following manner: a dispersing apparatus adapted to the consistency of the adjuvant (A2) is introduced, which makes it possible to avoid excess air entrainment the concentrated aqueous solution containing the dispersant D1 and optionally at least one other water-soluble or water-dispersible additive, this concentrated solution is brought to a temperature of the order of 60-800 ° C., and then the antifoam agent, the organic compound (C ) and, if necessary, a mineral stabilizer and / or a Bronsted acid. If necessary, this adjuvant (A2) is diluted with water in concentrated form. Also, if necessary, the pH of the adjuvant (A2) is adjusted by means of an acid or a base.

Another subject of the invention is the use
a dispersant (D1), water-soluble or
hydrodispersible, according to the invention, optionally in
combination with other additives;
- or, an adjuvant (A1) consisting of a combination of
dispersants (D1) and (D2), described above,
- or an adjuvant (A2) containing at least one dispersant
(D1), water-soluble or water-dispersible,
the invention, described above, for fluidizing and improving the homogeneity and maneuverability of cement compositions with reduced water content or an aqueous suspension of mineral particles.

In the following examples, other advantages and variations of the invention are described.

Example 1
Preparation of a dispersant by esterification Dartielle of a polyacrylic acid with a polyethylene methylene ether monofunctional.

Raw materials used - 120 g of poly (meth) acrylic acid marketed by BASF under the name Sokalan CLOS. Its weight average molecular weight is 4000 Daltons. It is diluted 50% in water; 252 g of a polyethylene glycol methyl ether (type
M750 from Hoechst) having a weight average molecular weight of 750 Daltons - 0.60 g of lithium hydroxide.

PREPARATION OF DISPERTER
In an enamelled reactor equipped with agitation, a distillation device and a partial evacuation system, the abovementioned raw materials are introduced in the following order - poly (meth) acrylic acid - lithium hydroxide; - Polyethylene glycol methyl ether (liquid product at 500C).

Upon completion of the introduction of the polyethylene glycol methyl ether, the reactor is placed under partial vacuum (20 to 30 mm Hg) with a nitrogen blanket. Then, heating to 60 ~ 75 C: we obtain the beginning of distillation of water supplied with poly (meth) acrylic acid. Then we raise the temperature to 165-17

If the results of these analyzes are in conformity, the reaction is stopped. To do this, the reactor is cooled to a temperature of the order of 800 ° C., then 4 g of oleic amine with 2 moles of ethylene oxide (marketed under the name Noramox 2 by CECA) and 4 g of tributyl phosphate are added. (antifoam). Finally, the product is diluted with water to obtain a solids content of 30% and neutralized with sodium hydroxide at pH: 6.9. The dispersant thus prepared is ready for use.

performances
The ready-to-use dispersant, at 30% solids content, is evaluated through workability measurements and measurements of compressive strength.

To do this, prepare a concrete comprising, in kg per 3 m of concrete - crushed gravel 12.5 / 20 mm: 474 - crushed gravel 8 / 12.5 mm: 352 - crushed gravel 4/8 mm: 189 - sand 2/4 mm: 135 - sand 1/4 mm: 127 - sand 0,5 / 1 mm: 79 - sand 0,375 / 1 mm: 166 - sand 0 / 0,375 mm: 234 - of the sand Sand 0 / 0.160 mm: 51 - Cormeilles CPA HP cement: 350 - x% by weight of the ready-to-use dispersant (at 30% solids), based on the quantity of cement; - water: 185

The concrete obtained is homogeneous, no phenomenon of segregation or bleeding is observed. In addition, it is easy to work and set up.

Maintaining the fluidity of the concrete was evaluated by measuring the fluidity over time (measurement of "slump") under the conditions of the standard P NF EN-12382, at t0 (just after concrete preparation) then at tO + 30 min., 60 + 60 min. and t0 +90 min.

The compressive strength was measured according to the standard
P NF EN-12 394.

The results obtained are grouped together in the following tables (I) and (II)
Table (I) - Measurement of workability

<tb><SEP>SEP>SEP> E / C <SEP> 8LUMP <SEP>% <SEP> Assay
<tb> dispersant <SEP> trains
<tb><SEP> x <SEP> (in <SEP> cm) <SEP>
<tb><SEP> (*)
<tb> (% <SEP> in <SEP> weight)
<tb><SEP> TO <SE> TO <SEP> + <SE> TO <SEP> + <SEP> TO: <SEP> + <SE> TO <SE> TO <SEP> +
<tb><SEP> 30 <SEP> 60 <SEP> 90 <SEP> 90
<tb><SEP> min. <SEP> min. <SEP> min. <SEP> min.
<Tb>

<SEP> 0.8 <SEP> 0.52 <SEP> 23 <SEP> 23 <SEP> 22 <SEP> 20 <SEP> 1.5 <SEP> 1.9
<tb><SEP> 0.53 <SEP> 0.52 <SEP> 19 <SEP> 17 <SEP> 11 <SEP> 2.6 <SEP> 2.7
<tb> (*) this percentage corresponds to the volume of air entrained on the total volume of concrete. The entrained air is measured using a concrete aerometer according to the air entrainment standard P NF 18353.

Table (II) - Compressive Resistors (Rc) at 200C
(expressed in MPa - accuracy of measurement 1%)

<tb><SEP><SEP>SEP> Rc <SEP> Rc <SEP> Rc Assay
<tb> dispersant <SEP> x <SEP> at <SEP> 24 <SEP> hours <SEP> at <SEP> 7 <SEP> days <SEP> at <SEP> 28 <SEP> days
<tb> (% <SEP> in <SEP> weight)
<tb><SEP> 0.8 <SEP> 16.7 <SEP> 31.2 <SEP> 41.5
<tb><SEP> 0.53 <SEP> | <SEP> 19.4 <SEP> 35.3 <SEP> 38.9
<Tb>
Examples 2 to 6
Preparation and evaluation of additives (Al) consisting of a combination of disin- dinants (D1) and (D2) in concretes.

The dispersant (D1) is obtained by reproducing most of the operating conditions stated in Example 1 to prepare the dispersant ready for use, except for the water dilution operation which is conducted so as to obtain a dry extract of 40%.

The dispersant (D2) is the product marketed under the name OPTIMA 100 by the company CHRYSO. This product contains a fluidizing compound containing at least one amino-alkylene phosphonic group and at least one polyoxyalkylated chain and has a dry extract equal to 30%.

In Examples 3 to 5, combinations of dispersants (D1) and (D2) were evaluated on concrete by varying the proportion by weight of the amount of dispersant (D1) over the amount of dispersant (D2) compared to the dispersant ( D1) alone (Example 2) and dispersant (D2) alone (Example 6).

<Tb>

Examples <SEP> proportion <SEP> of <SEP> Extract <SEP> sec <SEP> of
<tb><SEP> (D1) <SEP> on <SEP> (D2) <SEP> dispersant <SEP> or <SEP> of
<tb><SEP> mix <SEP> of
<tb><SEP> dispersants
<tb><SEP> (in <SEP>% <SEP> in <SEP> weight)
<tb><SEP> 2 <SEP> 100/0 <SEP> 40 <SEP>%
<tb><SEP> 3 <SEP> 90/10 <SEP> 30 <SEP>%
<tb><SEP> 4 <SEP> 75/25 <SEP> 30 <SEP>%
<tb><SEP> 5 <SEP> 60/40 <SEP> 30 <SEP>%
<tb><SEP> 6 <SEP> 0/100 <SEP> 30 <SEP>%
<Tb>
The workability, air entrainment and compressive strength measurements were made with the concrete formula given in Example 1 and with - 0.67% by wet weight of the dispersant (D1) in FIG. Example 2, or - 0.8 wt.% wet of one of the combinations of dispersants (D1) and (D2) indicated for Examples 3 to 5, or dispersant (D2) in Example 6.

The results obtained are collated in Tables (III) and (IV).

Table (III) - Workability measurement

<tb> Ex. <SEP> E / C <SEP> Maintenance <SEP> of Air Handling <SEP>% <SEP>
<tb><SEP> trained
<tb><SEP> TO <SEP> TO <SEP> + <SEP> TO <SEP> + <SEP> TO <SEP> + <SEP> TO <SEP> TO <SEP> +
<tb><SEP> 30 <SEP> 60 <SEP> 90 <SEP> 60
<tb><SEP> min. <SEP> min. <SEP> min. <SEP> min.
<Tb>

2 <SEP> 0.44 <SEP> 21 <SEP> 16 <SEP> 4 <SEP> 2.1 <SEP> 2.5
<tb> 3 <SEP> 0.54 <SEP> 21 <SEP> 23 <SEP> 23 <SEP> 21 <SEP> 2.1 <SEP> 2.4
<tb> 4 <SEP> 0.54 <SEP> 22 <SEP> 23 <SEP> 23 <SEP> 21 <SEP> 1.9 <SEP> 2,2
<tb> 5 <SEP> 0.54 <SEP> 22 <SEP> 23 <SEP> 22 <SEP> 20 <SEP> 1.9 <SEP> 2.4
<tb> 6 <SEP> 0.57 <SEP> 20 <SEP> 20 <SEP> 20 <SEP> 20 <SEP> 2.1 <SEP> 2.5
<Tb>
Table IV - Resistance in compression (Rc) at 200C
(expressed in MPa)

<tb> Examples <SEP> Rc <SEP> Rc <SEP> Rc
<tb><SEP> to <SEP> 24 <SEP> hours <SEP> to <SEP> 7 <SEP> days <SEP> to <SEP> 28 <SEP> days
<tb><SEP> 2 <SEP> 30.4 <SEP> 48.5 <SEP> 55.5
<tb><SEP> 3 <SEP> 17.7 <SEP> 32.4 <SEP> 37.1
<tb><SEP> 4 <SEP> 17.4 <SEP> 31.3 <SEP> 36.9
<tb><SEP> 5 <SEP> 17.1 <SEP> 31.3 <SEP> 36.6
<tb><SEP> 6 <SEP> 13.3 <SEP> 28.8 <SEP> 35.2
<Tb>
The concrete examples 2 to 6 are flowing, easy to implement and have little bleeding. In addition, the addition of the dispersant (D2) in the dispersant (D1) makes it possible to achieve a significant maintenance of the workability.

Compared with the dispersant (D2) alone, the dispersant combinations (D1) and (D2) lead to a greater water reduction, higher 24-hour strengths and slightly longer long-term strengths.

Examples 7 to 11
Preparation and evaluation of adnuvants (Al) consisting of a combination of disisersants (D1) and (D2) in grouts.

The dispersant (D1) described in Examples 2 to 6 is used. The dispersant (D2) is the product sold under the name OPTIMA 100 by the company CHRYSO.

In Examples 8 to 10, the fluidity of a slurry containing a combination of dispersants (D1) and (D2) is measured by varying the proportion by weight of dispersant (D1) over the dispersant (D2), compared with a grout containing only the dispersant (D1) (Example 7) and a slurry containing only the dispersant (D2) (Example 11).

<Tb>

Examples <SEP> Proportion <SEP> of <SEP> Extract <SEP> sec <SEP> of
<tb><SEP> (D1) <SEP> on <SEP> (D2) <SEP> dispersant <SEP> or <SEP> of
<tb><SEP> mix <SEP> of
<tb><SEP> dispersants
<tb><SEP> (in <SEP>% <SEP> in <SEP> weight)
<tb><SEP> 7 <SEP> 100/0 <SEP> 40 <SEP>%
<tb><SEP> 8 <SEP> 80/20 <SEP> 40 <SEP>%
<tb><SEP> 9 <SEP> 50/50 <SEP> 40 <SEP>%
<tb><SEP> 10 <SEP> 20/80 <SEP> 40 <SEP>%
<tb><SEP> 11 <SEP> 0/100 <SEP> 30 <SEP>%
<Tb>
The slurry is prepared by mixing in a kneader, at room temperature, the water (at about 200 ° C), the dispersant or the dispersant mixture, and the cement (it is the cement CPA 52.5 R of Val d' Azergues).

The water-to-cement ratio (W / C) of the slurry is equal to 0.32 and the amount of dispersant introduced into the slurry of Examples 7 to 10 is equal to 0.7% by weight (in wet), based on the amount of cement, in Example 11, and is equal to 1.25% by weight (wet) relative to the amount of cement.

The grouts obtained are homogeneous and self-leveling in the case of Examples 8 to 11.

The fluidity of the grouts was evaluated using the cone of
Marsh: it is a frustoconical mold of volume equal to 1.6 liters, with two openings, the lower opening of smaller diameter is provided with a cylindrical nozzle of 50 mm height and 10 mm in diameter . The conditions for measuring the fluidity are as follows: after moistening the Marsh cone and closing the outlet of the Marsh cone, at the nozzle, the grout is poured into the Marsh cone to the mark corresponding to a volume of 1 liter. The flow time of the slurry is then measured by the nozzle from a time (t) corresponding to the time (t0) of filling the cone plus the time of maintenance of the grout in the cone.

In addition, the tap start (D.P.), end of set (F.P.) and set (TPS.P.) times were measured on each slurry placed in a frustoconical cup. After having leveled the surface of the cup filled with grout, the cup is placed in an automatic measuring instrument equipped with a needle and a moving part in accordance with standard NF P-15414. This test then involves dropping the needle into the cup.

It is considered that - the beginning of the setting is carried out as soon as the depression of the needle is stopped at least 2.5 mm from the bottom of the cup; the end of the setting is carried out after the time when the needle does not penetrate, for the first time, more than 2.5 mm below the leveled surface of the cup.

The results obtained are shown in Table V below.

<tb> Ex. <SEP> Flow Time <SEP><SEP> Time <SEP> of <SEP> Take
<tb><SEP> in <SEP> minutes <SEP> in <SEP> hours <SEP> and <SEP> minutes
<tb><SEP> T0 <SEP> T = 30 <SEP> T = 1 <SEP> h <SEP> T = 2 <SEP> h <SEP> T = 3 <SEP> h <SEP> T = 4 <SEP> h <SEP> DP <SEP> FP <SEP> TPS.
<tb><SEP> min. <SEP> P.
<Tb>

7 <SEP> - <SEP> 11 <SEP> 13.5 <SEP> 20 <SEP> - <SEP> - <SEP> nm <SEP> nm <SEP> nm
<Tb>

<SEP> 24 <SEP> 10 <SEP> 10 <SEP> 10.7 <SEP> 11.1 <SEP> 12.6 <SEP> 12:43 <SEP> 19h05 <SEP> 6h22
<tb> 9 <SEP> 20 <SEP> 11 <SEP> 10 <SEP> 10.5 <SEP> 10.6 <SEP> 11.6 <SEP> 12.25 <SEP> 18.55 <SEP> 6.30
<tb> 10 <SEP> 14 <SEP> 10.2 <SEP> 10 <SEP> 9.5 <SEP> 10 <SEP> 10.5 <SEP> 17:23 <SEP> 21:45 <SEP> 4h22
<tb> 11 <SEP> 12.5 <SEP> 10.2 <SEP> 14.2 <SEP> 13.8 <SEP> 13.1 <SEP> 13.2 <SEP> nm <SEP> nm <SEP > nm
<tb> nm means no measure.

Example 12 Evaluation of the dispersant (D1) of Example 2 in a concrete composition for prefabrication.

To do this, prepare a concrete comprising, in kg per m of concrete: - crushed gravel 12.5 / 20 mm: 380 - crushed gravel 8 / 12.5 mm: 280 - crushed gravel 4/8 mm: 420 - sand 2/4 mm: 57 - sand 1/4 mm: 250 - sand 0,5 / 1 mm: 130 - sand 0,315 / 1 mm: 200 - sand 0 / 0,315 mm: 100 - of the sand sand 0 / 0.160 mm: 80 - CPA cement Cormeilles CP: 400 - 0.25% by dry weight of the dispersant (D1) relative to the amount of cement - water: 180
This concrete is poured into cubic molds of 14 cm side and is baked under the following conditions: 1 hour at 40 ° C, temperature rise from 400C to 800C in 1h30 min., Maintained at 800C for 2 hours Finally, the temperature decreases from 800C to 400C in 1h30 min.

The compressive strength of the cured concrete was measured under the conditions of the standard P NF EN-12394 after a time (t) counted from the pouring of the concrete in the cubic mold. The results are summarized in Table VI below.

<tb><SEP> Example <SEP> Resistance <SEP> in <SEP> Compression <SEP> (in <SEP> MPa) <SEP> After
<tb><SEP> 6 <SEP> hours <SEP> 24 <SEP> hours <SEP> 7 <SEP> days <SEP> 28 <SEP> days
<tb> Example <SEP> 12 <SEP> 36.2 <SEP> 44.5 <SEP> 63.3 <SEP> 69.9
<Tb>
Examples 13 to 24
Procedure for the preparation of the dispersants of Examples 13 to 22.

Raw materials used.

a dispersion at 30% in water of polyacrylic acid obtained by polymerization of x moles of acrylic acid and 1 mole of thioglycolic acid; one or more polyethylene glycol methyl ether comprising, on average, y functions as ethers ; 1 mol% of sodium hydroxide per carboxylic function of the polyacrylic acid.

Dispersant preparation
In a reactor equipped with stirring, a distillation device and a partial evacuation system, the sufficient amounts of the abovementioned raw materials are introduced, depending on the desired esterification rate. The reactor is placed under partial vacuum (20 to 30 mmHg). Then, the temperature of the reaction medium is raised to remove by distillation the water supplied with the acrylic acid. The temperature is then raised to about 1750C to effect the esterification reaction.

The duration of the esterification reaction is of the order of 5 hours.

After esterification, the reaction medium which contains the esterified polyacrylic acid is used as such as a dispersant.

Evaluation
The dispersants were evaluated by means of pasting measures of cement paste containing CPA HTS cement.
Teil, the dispersant and the mixing water (the E / C ratio is 0.26). The cement pastes are prepared manually and the dispersant is introduced into the mixing water.

For the evaluation of this paste, the cement paste is introduced into a cylinder of diameter equal to 51 mm and height equal to 32 mm, the lower end has been closed. After filling the cylinder, the lower end is released and the diameter of the wafer obtained is measured, along 3 axes, after stabilization. At the lowest spreading values, the diameter of the wafers is obtained with an accuracy of plus or minus 1 mm, and an accuracy of plus or minus 2 mm from 220 mm in diameter.

The value given in the table below is the average of the values measured along 3 axes.

Other structural characteristics of the dispersants and the results obtained are given in the table below.

<tb><SEP> Ex. <SEP> Characteristics <SEP> Initial <SEP> Stories
<tb><SEP> of <SEP> dispersant <SEP> (in <SEP>) <SEP> in <SEP> function
<tb><SEP> of the <SEP> assay <SEP> in
<tb><SEP> say <SEP> pouring <SEP>
<tb><SEP> X <SEP> Y <SEP> Rate <SEP> 0.3 <SEP>% <SEP> 0.1 <SEP>%
<tb><SEP> of esterifi- <SEP> (b) <SEP> (b)
<tb><SEP> cation <SEP> (a)
<tb><SEP> 13 <SEP> 19 <SEP> 17 <SEP> 32 <SEP>% <SEP> 258 <SEP> 204
<tb><SEP> 14 <SEP> 34 <SEP> 17 <SEP> 30 <SEP>% <SEP> 253 <SEP> 158
<tb><SEP> 15 <SEP> 34 <SEP> 17 <SEP> 37 <SEP>% <SEP> 237 <SEP> 146
<tb><SEP> 16 <SEP> - <SEP> 9 <SEP> 17 <SEP> 30 <SEP>% <SE> 251 <SEP> 159
<tb><SEP> 17 <SEP> 19 <SEP> 17 <SEP> 40 <SEP>% <SEP> - <SEP> 206
<tb><SEP> 18 <SEP> 19 <SEP> 17 <SEP> 50 <SEP>% <SEP> - <SEP> 156
<tb><SEP> 19 <SEP> 19 <SEP> 11 <SEP> 28 <SEP>% <SEP> - <SEP> 172
<tb><SEP> 20 <SEP> 19 <SEP> 11 <SEP> 40 <SEP>% <SEP> - <SEP> 183
<tb><SEP> 21 <SEP>. <SEP> 19 <SEP> 8 <SEP> 30 <SEP>% <SEP> - <SEP> 186
<tb><SEP> 22 <SEP> 19 <SEP> 8 <SEP> 38 <SEP>% <SEP> - <SEP> 184
<tb> 23 <SEP> (*) <SEP> - <SEP> - <SEP> - <SEP> 224 <SEP> 58
<tb> 24 <SEP> (*) <SEP> - <SEP> - <SEP> - <SEP> 201 <SEP> 65
(a) the esterification rate is referred to the total number of carboxylic functions of the polyacrylic acid of interest.

(b) these dosages are expressed by weight of dry dispersant on the weight of cement.

(*) Examples 23 and 24 are comparative examples.

In Example 23, the dispersant used is the GT resin marketed by CHRYSO. It is a polysulfonate based on melamine. In Example 24, it is a 30% diphosphonated dispersant in water, of formula

Examples 25 to 37
The procedure used in the preparation of the dispersants of Examples 25 to 36 is identical to that indicated for the dispersants of Examples 13 to 22. The dispersant used in Example 37 corresponds to the dispersant described in Example 1.

The evaluation of the dispersants of Examples 25 to 37 was carried out on cement paste under the conditions set forth for Examples 13 to 24, with the following differences: the cement pastes are prepared with Cormeilles CPA HP cement with a water ratio on cement (E / C) equal to 0.36 and a dispersant dosage equal to 0.24%, expressed as dry dispersant relative to the weight of cement.

The other structural characteristics of the dispersants and the results obtained are given in the table below.

<Tb>

Ex. <SEP> | <SEP><SEP><SEP> Features | <SEP> Spreading <SEP> (in <SEP> mm)
<tb><SEP> dispersant <SEP> after <SEP> maintenance <SEP> of <SEP> the <SEP> paste <SEP> during <SEP> a
<tb><SEP> time <SEP> t <SEP> (in <SEP> nin.) <SEP> in <SEP> the <SEP> cylinder
<tb><SEP> x <SEP> y <SEP> Rate <SEP> 0 <SEP> 30 <SEP> 60 <SEP> 90 <SEP> 120 <SEP> 150
<tb><SEP> of eetéri- <SEP> min. <SEP> min. <SEP> min. <SEP> min. <SEP> min. <SEP> min.
<tb><SEP> fication
<tb> 25 <SEP> 9 <SEP> 17 <SEP> 30 <SEP>% <SEP> 167 <SEP> 126 <SEP> 89 <SEP> 77 <SEP> - <SEP> - <SEP>
<tb> 26 <SEP> 19 <SEP> 17 <SEP> 32 <SEP>% <SEP> 191 <SEP> 164 <SEP> 94 <SEP> 75 <SEP> - <SEP> - <SEP>
<tb> 27 <SEP> 29 <SEP> 17 <SEP> 28 <SEP>% <SEP> 201 <SEP> 209 <SEP> 116 <SEP> 77 <SEP> - <SEP> - <SEP>
<tb> 28 <SEP> 19 <SEP> 17 <SEP> 50 <SEP>% <SEP> 168 <SEP> 222 <SEP> 230 <SEP> 230 <SE> 219 <SEP> 195
<tb> 29 <SEP> 29 <SEP> 17 <SEP> 49 <SEP>% <SEP> 183 <SEP> 227 <SEP> 236 <SEP> 229 <SEP> - <SEP> - <SEP>
<tb> 30 <SEP> 29 <SEP> 17 <SEP> 59 <SEP>% <SEP> 126 <SEP> 213 <SEP> 225 <SEP> 221 <SEP> 195 <SEP> - <SEP>
<tb> 31 <SEP> 34 <SEP> 17 <SEP> 37 <SEP>% <SEP> 198 <SEP> 205 <SEP> 130 <SEP> - <SEP> - <SEP>
<tb> 32 <SEP> 34 <SEP> 17 <SEP> 50 <SEP>% <SEP> 196 <SEP> 241 <SEP> 241 <SEP> 233 <SEP> 215 <SEP> - <SEP>
<tb> 33 <SEP> 34 <SEP> 17 <SEP> 55 <SEP>% <SEP> 182 <SEP> 239 <SEP> 229 <SEP> 223 <SEP> 214 <SEP> - <SEP>
<tb> 34 <SEP> 19 <SEP> 17 <SEP> 34 <SEP>% <SEP> 189 <SEP> 231 <SEP> 227 <SEP> 194 <SEP> - <SEP> - <SEP>
<tb> 35 <SEP> 19 <SEP> 11 <SEP> 44 <SEP>% <SEP> 175 <SEP> 227 <SEP> 162 <SEP> 112 <SEP> - <SEP> - <SEP>
<tb> 36 <SEP> 19 <SEP> 8 <SEP> 38 <SEP>% <SEP> 155 <SEP> 132 <SEP> 85 <SEP> 64 <SEP> - <SEP> - <SEP>
<tb> 37 <SEP> - <SEP> - <SEP> - <SEP> 124 <SEP> 212 <SEP> 214 <SEP> 216 <SEP> - <SEP>
Examples 38 to 42
The procedure used for the preparation of the dispersants of Examples 38 to 42 is identical to that indicated for the dispersants of Examples 13 to 22, the only difference being that in Examples 38 to 41, a mixture of two methylethers is used. of polyethylene glycol having respectively (yl) and (y2) ether functions and each leading respectively to a degree of esterification (such) and (te2), expressed in% based on the number of carboxylic functions of the starting polyacrylic acid.

The other structural characteristics of the dispersants and the results obtained are reported in the table below.

The dispersants of Examples 38 to 42 were evaluated through spreading measurements, with cement pastes identical to those of Examples 25 to 37 and under the same conditions.

<Tb>

<SEP> Ex. <SEP> | <SEP> Characteristics <SEP> of <SEP> dispersant <SEP> | <SEP> Stages <SEP> (in <SEP> mm) <SEP> after
<tb><SEP> naintion <SEP> of <SEP> the <SEP> paste <SEP> in <SEP> the
<tb><SEP> cylinder <SEP> during <SEP> a <SEP> time <SEP> t
<tb> on <SEP> X <SEP><SEP> Min. <September>
<tb><SEP> x <SEP> yl <SEP> as <SEP> y2 <SEP> te2 <SEP> 0 <SEP> 30 <SEP> 60 <SEP> 90
<tb><SEP> min. <SEP> min. <SEP>. <SEP> min. <SEP> min.
<Tb>

<SEP> 38 <SEP> 19 <SEP> 17 <SEP> 30 <SEP> 3 <SEP> 20 <SEP> 191 <SEP> 240 <SE> 251 <SEP> 252
<tb><SEP> 39 <SEP> 34 <SEP> 17 <SEP> 20 <SEP> 3 <SEP> 30 <SEP> 247 <SEP> 247 <SEP> 248 <SEP> 217
<tb><SEP> 40 <SEP> 39 <SEP> 17 <SEP> 30 <SEP> 3 <SEP> 20 <SEP> 234 <SE> 245 <SE> 245 <SEP> 233
<tb><SEP> 41 <SEP> 59 <SEP> 17 <SEP> 30 <SEP> 3 <SEP> 20 <SEP> 224 <SEP> 235 <SE> 233 <SE> 192
<tb><SEP> 42 <SEP> 34 <SEP> 17 <SEP> 50 <SEP> 0 <SEP> 0 <SEP> 196 <SEP> 241 <SEP> 241 <SEP> 233
<Tb>
Examples 43 to 53
The procedure used to prepare the dispersants of Examples 43 to 52 is shown in Examples 13 to 22 and 38 to 42. The dispersants of Examples 43 to 53 are evaluated through spread measurement (see conditions in Examples 13). to 24) in aluminous cement pastes containing - "FONDU" brand cement of the group
LAFARGE; water, in a water-to-cement ratio of 0.22; dispersant at a rate of 0.2% by weight in dry matter based on the weight of cement.

The mixing time lasts 1.5 minutes. The other structural characteristics of the dispersants and the results obtained are reported in the table below.

<SEP> Ex. <SEP> Characteristics <SEP> of the <SEP> dispersant <SEP> Etalesents <SEP> initial
<tb><SEP> (in <SEP> mm) <SEP>
<tb> x <SEP> x <SEP> yl <SEP> such <SEP> y2 <SEP> te2
<tb><SEP> 43 <SEP> 19 <SEP> 45 <SEP> 32 <SEP> 0 <SEP> 0 <SEP> 223
<tb><SEP> 44 <SEP> 19 <SEP> 45 <SEP> 34 <SEP> 0 <SEP> 0 <SEP> 220
<tb><SEP> 45 <SEP> 19 <SEP> 12 <SEP> 17 <SEP> 0 <SEP> 0 <SEP> 217
<tb><SEP> 46 <SEP> 19 <SEP> 17 <SEP> 30 <SEP> 3 <SEP> 20 <SEP> 213
<tb><SEP> 47 <SEP> 34 <SEP> 17 <SEP> 20 <SEP> 3 <SEP> 30 <SEP> 213
<tb><SEP> (*)
<tb><SEP> 48 <SEP> 19 <SEP> 17 <SEP> 51 <SEP> 0 <SEP> 0 <SEP> 211
<tb><SEP> (*)
<tb><SEP> 49 <SEP> 29 <SEP> 17 <SEP> 29 <SEP> 0 <SEP> 0 <SEP> 207
<tb><SEP> 50 <SEP> 59 <SEP> 17 <SEP> 30 <SEP> 3 <SEP> 20 <SEP> 207
<tb><SEP> 51 <SEP> 29 <SEP> 17 <SEP> 60 <SEP> 0 <SEP> 0 <SEP> 205
<tb><SEP> (*)
<tb><SEP> 52 <SEP> 19 <SEP> 17 <SEP> 30 <SEP> 0 <SEP> 0 <SEP> 201
<tb><SEP> 53 <SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP> 200
<tb><SEP> (**)
(*) the pH of these dispersants was brought to pH 7 by addition of sodium hydroxide (**) the dispersant used in Example 53 is the diphosphonated dispersant used in Example 24.

Claims (20)

 carboxylic acid of said polycarboxylic acid.  free hydroxyl that can react with a function  - and at least one polyether containing a group  carboxylic acids per molecule;  saturated, containing on average at least 6 functions  polymerizing at least one non-carboxylic acid  at least one polycarboxylic acid obtained in  of a base, by reacting  partial esterification catalyzed by the introduction  characterized in that this dispersant is obtained by  totally salified and polyether chains,  carboxylic acids, possibly partially or  mineral particles, containing functions  cement composition and aqueous suspensions of  1. Water-soluble or water-dispersible dispersant for 2. Dispersant according to claim 1, characterized in that  that the base is sodium hydroxide. 3. Dispersant according to claim 1, characterized in that  that the base is lithium hydroxide. 4. Dispersant according to any one of claims 1  at 3, characterized in that 10 to 90% of the functions  carboxylic acids available from polycarboxylic acid  are esterified. 5. Dispersant according to claim 4, characterized in that  that 30 to 70% of the available carboxylic functions  polycarboxylic acid are esterified. 6. Dispersant according to any one of the claims  preceding, characterized in that its weight  average molecular weight, measured by chromatography  liquid by gel permeation, with a calibration  polyethylene glycol, varies between about 1000 and  about 1,000,000, preferably about 10,000  and about 80,000. 7. Dispersant according to any one of the claims  preceding, characterized in that the acid  polycarboxylic acid is obtained by polymerization of a  monomer mixture containing as an essential component  acrylic acid and / or methacrylic acid and,  optionally, at least one other monomer at one or  several ethylenic unsaturations that can be  copolymerized with acrylic acid and acid  methacrylic. 8. Dispersant according to claim 7, characterized in that  that the polycarboxylic acid is obtained by  polymerization of acrylic acid and acid  methacrylic. 9. Dispersant according to claim 7, characterized in that  that the polycarboxylic acid is obtained by  acrylic acid polymerization. 10. Dispersant according to any one of the claims  previous ones, characterized in that the polyether is a  polyalkylene glycol alkyl ether, preferably a  polyalkylene glycol alkyl ether mixture of  formula XO (YO) nH in which  X represents an alkyl group of 1 to 8 atoms of  carbon, preferably from 1 to 4 carbon atoms,  even better, X is a methyl radical;  Y represents an alkylene group of 2 to 4 carbon atoms  carbon or a mixture of these alkylene groups;  n is an integer ranging from 3 to 500;  the polyalkylene glycol alkyl ether or the mixture  of polyalkylene glycol alkyl ethers is such that  the average molar ratio of oxyethylene units  oxyalkylene units (YO) varies from approximately  0.5 to 1, still more preferably 0.7 to 1. 11. Dispersant according to claim 10, characterized in  what the polyether is made of  one or more polyethylene alkyl ethers  glycol, possibly containing units  oxypropylenes, distinguished by their weight  average molecular weight, and / or  one or more polypropylene alkylethers  glycol, containing oxyethylene units, is  distinguishing by their average molecular weight in  weight. 12. Dispersant according to claim 11,  characterized in that the polyether is a methylether  of polyethylene glycol containing from about 10 to  150 oxyethylene units, or a mixture of  Polyethylene glycol methyl ethers differing  basically by the length of the pattern chain  oxyethylenes, this mixture comprising, on average,  molecule, of the order of 5 to 50 oxyethylene units. 13. Method of manufacturing a dispersant according to one  any of claims 1 to 12, characterized in  what is reacted, in the presence of water and a  base, at a temperature between 160 and 2000C  at least one polycarboxylic acid obtained by  polymerization of at least one carboxylic acid  unsaturated, containing on average at least six  carboxylic functions per molecule  - and at least one polyether containing a group  free hydroxyl that can react with a function  carboxylic acid of said polycarboxylic acid. 14. A combination of dispersing agents characterized in that  it consists of at least one dispersant defined in any one of claims 1 to 12 and at least one dispersant, water-soluble or water-dispersible, comprising at least one amino-alkylene phosphonic group, optionally salified, and at least one chain polyoxyalkylated, and having the formula

 in which  R is a hydrogen atom or a group  monovalent hydrocarbon saturated or not  from 1 to 18 carbon atoms and optionally one or  several heteroatoms,  the Ri's are similar or different to each other and  represent an alkylene such as ethylene,  propylene, butylene, amylene, octylene or  cyclohexene, or an arylene such as styrene or  methylstyrene; the Ri may contain a  or more heteroatoms,  Q is a hydrocarbon group having from 2 to 18  carbon atoms and possibly one or more  heteroatoms,  A is an alkylidene group having from 1 to 5  carbon atoms. the Rj are similar or different from each other and  can be chosen from:  * the group A-P03H2, A having the meaning  supra,  the alkyl group having from 1 to 18 inclusive  carbon atoms and can carry  [R-O (Ri-O) n] groups, R and R 1 having the  aforementioned meanings,  * and the group

 contain one or more other heteroatoms.  cycles, this or these cycles may furthermore  Q, N and Rj may together form one or more  yt is an integer between 1 and 3,  the sum "r + q" is between 1 and 10,  by Q,  "q" is the number of groups [R-O (Ri-O) n] carried  by the set of Rj,  "r" is the number of groups [R-O (R1-O> n] carried  "n" is a number greater than 0,  carbon,  having from 2 to 18 inclusive atoms of  - B denoting an alkylene group  - Rk designating a group such as Rj, 15. Combination of dispersing agents according to  claim 14, characterized in that the  dispersant, water-soluble or water-dispersible,  having at least one amino-alkylene group  phosphonic acid, possibly salified, and at least one  polyoxyalkylated chain, meets the formula

 * and the group  * CH2-PO3H2 group  the Rj are similar or different from each other and can be selected from  A is the methylene group  R 1 represents ethylene or propylene or a mixture of ethylene and propylene. Preferably, 60 to 100% of the R1 are ethylene groups. Q is a hydrocarbon group having 2 to 8 carbon atoms and optionally one or more heteroatoms  R is a hydrogen atom or a monovalent hydrocarbon group, saturated or unsaturated, having from 1 to 8 carbon atoms and, optionally, one or more heteroatoms  in which  . "y" is. an integer equal to 1 or 2.  "q" is an integer equal to 1 or 2,  . "n" is an integer between 10 and 250,  2 to 4 carbon atoms,  B denotes an alkylene group containing  - Rk denoting a phosphonic group such as Rj, 16. Adjuvant for aqueous suspensions of particles  mineral and mixtures based on hydraulic binder,  characterized in that it is in the form of a mixture  uniform including  - some water ;  at least one water-insoluble anti-foam agent or  weakly water soluble  at least one water-soluble dispersant or  hydrodispersible, defined in any of the  Claims 1 to 12, possibly in  combination with at least one dispersant,  water-soluble or water-dispersible  at least one amino-alkylene phosphonic group,  possibly salified, and at least one chain  polyoxyalkylated, and corresponding to the stated formula  in claim 14  at least one organic compound (C) containing  at least one primary amine function,  secondary or tertiary, possibly  partially or totally neutralized by a  Bronsted acid, organic or mineral  and at least one alkyl or alkyl chain  aryl, linear or branched, saturated or  unsaturated, comprising at least 8 atoms of  carbon, and possibly heteroatoms,  selected from oxygen, sulfur or nitrogen  - at least one mineral stabilizer when the pH  said mixture is greater than 7  - optionally, an acid or a base for  adjust the pH of said mixture. 17. Adjuvant according to claim 16, characterized in that  that the mineral stabilizer is sepiolite. 18. Use of a dispersant according to any one of  claims 1 to 12 or a combination of  dispersants according to claim 14 or 15 or a  adjuvant according to claim 16 or 17, for  streamline and improve the homogeneity and  workability of water-content cement compositions  reduced and aqueous suspensions of particles  mineral. 19. Cement compositions comprising a dispersant according to  any one of claims 1 to 12, or a  dispersant combination according to claim 14  or 15, or an adjuvant according to claim 16 or 17. 20. Aqueous suspensions of mineral particles  comprising a dispersant according to any of  claims 1 to 12, or a combination of  dispersants according to claim 14 or 15, or a  adjuvant according to claim 16 or 17.